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Abstract:

An apparatus and method efficiently integrating inductive and conductive
charging systems, including embodiments directed towards enabling user
selection of either, or both, of conductive and inductive charging.
Conductive charging and inductive charging both have, in certain contexts
or when judged by different criteria, advantages over the other. Systems
and methods relying on one or the other would not have as wide-spread
value to a user with opportunities to access both types of charging
modalities.

Claims:

1. A charging system for an energy storage system of an apparatus,
comprising: a conductive rectifier stage wholly disposed on the
apparatus, said conductive rectifier stage including a first inverter
switching circuit coupled to a first primary winding of an isolation
transformer and a first output smoothing circuit coupled to both a first
secondary winding of said isolation transformer and to the energy storage
system, said conductive rectifier stage rectifying a first AC line
voltage conductively received at the apparatus wherein said first
inverter switching circuit is responsive to a first control signal; a
partial inductive rectifier stage wholly disposed on the apparatus, said
partial inductive rectifier stage part of an inductive rectifier stage
partially disposed on the apparatus, said inductive rectifier stage
including a second inverter switching circuit coupled to a second primary
winding of an induction transformer and a second output smoothing circuit
coupled to both a second secondary winding of said induction transformer
and to the energy storage system, said inductive rectifier stage
rectifying a second AC line voltage not conductively received at the
apparatus wherein said second inverter switching circuit is wholly
disposed off the apparatus and wherein said second inverter switching
circuit is responsive to a second control signal; and a controller
communicated to said rectifier stages to provide said first control
signal and said second control signal.

2. The charging system of claim 1 wherein said controller includes a
master controller and a slave controller, said master controller
communicated to said conductive rectifier stage to provide said first
control signal and wirelessly communicated to said slave controller
wherein said slave controller is communicated to said second inverter
switching circuit to provide said second control signal wherein said
master controller is disposed on the apparatus and said slave controller
is disposed off the apparatus.

3. The system of claim 1 wherein said inverter switching circuits each
include a plurality of semiconductor power switching devices and wherein
said control signals include modulation control signals for said
plurality of semiconductor power switching devices.

4. The system of claim 1 further comprising an electromagnetic
interference (EMI) filter coupled between said output smoothing circuits
and the energy storage system.

5. The system of claim 1 wherein said first output smoothing circuit
includes a smoothing capacitance in parallel with the energy storage
system.

6. The system of claim 5 wherein said second output smoothing circuit is
coupled in parallel to both said first output smoothing circuit and to
said smoothing capacitance.

7. The system of claim 6 wherein each said output smoothing circuit
includes a diode bridge coupled in parallel to said smoothing
capacitance.

8. The system of claim 1 further comprising a snubber circuit coupled to
both said output smoothing circuits.

9. The system of claim 6 further comprising a snubber circuit coupled to
both said output smoothing circuits.

10. The system of claim 1 wherein said first output smoothing circuit
includes a first inductance.

11. The system of claim 10 wherein said second output smoothing circuit
includes said first inductance, wherein said first output smoothing
circuit provides a first quantity of instantaneous power, wherein said
second output smoothing circuit provides a second quantity of
instantaneous power and wherein said first inductance is sized to store a
maximum of a sum of said quantities of instantaneous power from both said
rectifier stages when both said rectifier stages are operated
concurrently.

12. The system of claim 10 wherein said second output smoothing circuit
includes said first inductance, wherein said first output smoothing
circuit provides a first quantity of instantaneous power, wherein said
second output smoothing circuit provides a second quantity of
instantaneous power and wherein said first inductance is sized to store a
maximum instantaneous power of either of said quantities of instantaneous
power from said rectifier stages when said rectifier stages are operated
non-concurrently.

13. The system of claim 10 wherein said second output smoothing circuit
includes a second inductance.

14. The system of claim 13 wherein said first output smoothing circuit
provides a first quantity of instantaneous power, wherein said second
output smoothing circuit provides a second quantity of instantaneous
power, wherein said first inductance is sized to store a maximum of said
first quantity of instantaneous power, and wherein said second inductance
is sized to store a maximum of said second quantity of instantaneous
power.

15. The system of claim 2 further comprising a sensing system collecting
a first set of charging parameters and wherein said controller is
responsive to said first set of charging parameters when providing said
control signals.

16. The system of claim 15 wherein said sensing system includes a first
AC voltage sensor coupled to said first AC line voltage, a first AC
current sensor coupled between said first AC line voltage and said first
inverter switching circuit, a battery current sensor coupled to said
first output smoothing circuit, and a battery voltage sensor coupled to
the energy storage system.

17. The system of claim 16 wherein said controller wirelessly receives a
second set of charging parameters from said inductive rectifier stage.

18. The system of claim 1 further comprising a power connector and a
relay directly coupling said second secondary winding to said first
secondary winding.

19. A charging method for an energy storage system of an apparatus, the
method comprising the steps of: a) rectifying a first AC line voltage
conductively received at the apparatus using a conductive rectifier stage
wholly disposed on the apparatus, said conductive rectifier stage
including a first inverter switching circuit coupled to a first primary
winding of an isolation transformer and a first output smoothing circuit
coupled to both a first secondary winding of said isolation transformer
and to the energy storage system wherein said first inverter switching
circuit is responsive to a first control signal; b) rectifying a second
AC line voltage not conductively received at the apparatus using an
inductive rectifier stage partially disposed on the apparatus, said
inductive rectifier stage including a second inverter switching circuit
coupled to a second primary winding of an induction transformer and a
second output smoothing circuit coupled to both a second secondary
winding of said induction transformer and to the energy storage system
wherein said second inverter switching circuit is wholly disposed off the
apparatus and wherein said second inverter switching circuit is
responsive to a second control signal; and c) communicating said control
signals to said inverter switching circuits from a controller having a
master controller wholly disposed on the apparatus.

20. A charging method for an energy storage system of an apparatus, the
method comprising the steps of: a) evaluating whether a conductive
rectifier stage wholly disposed on the apparatus is energized from a
first AC line voltage wherein said conductive rectifier stage includes a
first output smoothing circuit including a plurality of components; b)
evaluating whether an inductive rectifier stage partially disposed on the
apparatus is energized from a second AC line voltage wherein a second
output smoothing circuit of said inductive rectifier stage disposed on
the apparatus is coupled to said first output smoothing circuit and
shares at least one component of said plurality of components; and c)
charging the energy storage system using any rectifier stage that has
evaluated as being energized.

Description:

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to charging an energy
storage system, and more particularly but not exclusively, to an
integrated charging system employing both conductive and inductive modes.

[0002] Many high-performance energy storage solutions now employ
series-connected modules that, in turn, are series and parallel
combinations of individual battery cells. Battery packs used with
electric vehicles store large amounts of energy in a small space,
producing high energy densities. The energy is converted into mechanical
energy by the power train to move the vehicle, among other uses.

[0003] Conventional charging systems employ either a conductive system or
an inductive system. For electric vehicle implementations, it has become
a current standard to use conductive charging system for transferring
energy into the energy storage system. There are some advantages to use
of inductive charging systems which has resulted in after-market products
to add parallel inductive charging systems.

[0004] Electric vehicles are particularly known for having tight budgets
on size, weight, and cost, which are often interrelated. Simply adding an
entire parallel inductive charging system to a vehicle, either during
manufacture or after-market risks degrading performance, safety, and
reliability.

[0005] What is needed is an apparatus and method for efficiently
integrating inductive and conductive charging systems.

BRIEF SUMMARY OF THE INVENTION

[0006] Disclosed is an apparatus and method efficiently integrating
inductive and conductive charging systems. The present invention includes
embodiments directed towards enabling user (or automatic) selection of
either, or both, of conductive and inductive charging. Conductive
charging and inductive charging both have, in certain contexts or when
judged by different criteria, advantages over the other. Systems and
methods relying on one or the other would not have as wide-spread value
to a user with opportunities to access both types of charging modalities.
Embodiments of the present invention advantageously merge and integrate
both modalities to reduce added complexity, size, and weight while
preserving efficiency and improving usefulness. Disclosed are systems and
methods for integrated conductive and inductive charging. A charging
system for an energy storage system of an apparatus includes a conductive
rectifier stage wholly disposed on the apparatus, the conductive
rectifier stage including a first inverter switching circuit coupled to a
first primary winding of an isolation transformer and a first output
smoothing circuit coupled to both a first secondary winding of the
isolation transformer and to the energy storage system, the conductive
rectifier stage rectifying a first AC line voltage conductively received
at the apparatus wherein the first inverter switching circuit is
responsive to a first control signal; a partial inductive rectifier stage
wholly disposed on the apparatus, the partial inductive rectifier stage
part of an inductive rectifier stage partially disposed on the apparatus,
the inductive rectifier stage including a second inverter switching
circuit coupled to a second primary winding of an induction transformer
and a second output smoothing circuit coupled to both a second secondary
winding of the induction transformer and to the energy storage system,
the inductive rectifier stage rectifying a second AC line voltage not
conductively received at the apparatus wherein the second inverter
switching circuit is wholly disposed off the apparatus and wherein the
second inverter switching circuit is responsive to a second control
signal; and a controller communicated to the rectifier stages to provide
the first control signal and the second control signal.

[0007] A charging method for an energy storage system of an apparatus
includes a) rectifying a first AC line voltage conductively received at
the apparatus using a conductive rectifier stage wholly disposed on the
apparatus, the conductive rectifier stage including a first inverter
switching circuit coupled to a first primary winding of an isolation
transformer and a first output smoothing circuit coupled to both a first
secondary winding of the isolation transformer and to the energy storage
system wherein the first inverter switching circuit is responsive to a
first control signal; b) rectifying a second AC line voltage not
conductively received at the apparatus using an inductive rectifier stage
partially disposed on the apparatus, the inductive rectifier stage
including a second inverter switching circuit coupled to a second primary
winding of an induction transformer and a second output smoothing circuit
coupled to both a second secondary winding of the induction transformer
and to the energy storage system wherein the second inverter switching
circuit is wholly disposed off the apparatus and wherein the second
inverter switching circuit is responsive to a second control signal; and
c) communicating the control signals to the inverter switching circuits
from a controller having a master controller wholly disposed on the
apparatus.

[0008] A charging method for an energy storage system of an apparatus
includes a) evaluating whether a conductive rectifier stage wholly
disposed on the apparatus is energized from a first AC line voltage
wherein the conductive rectifier stage includes a first output smoothing
circuit including a plurality of components; b) evaluating whether an
inductive rectifier stage partially disposed on the apparatus is
energized from a second AC line voltage wherein a second output smoothing
circuit of the inductive rectifier stage disposed on the apparatus is
coupled to the first output smoothing circuit and shares at least one
component of the plurality of components; and c) charging the energy
storage system using any rectifier stage that has evaluated as being
energized.

[0009] Features/benefits include a user to employ any available charging
solution, whether it is a conductive charger and/or an inductive charger
when charging an energy storage solution such as battery packs used in
electric vehicles and similar applications. Other features, benefits, and
advantages of the present invention will be apparent upon a review of the
present disclosure, including the specification, drawings, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying figures, in which like reference numerals refer to
identical or functionally-similar elements throughout the separate views
and which are incorporated in and form a part of the specification,
further illustrate the present invention and, together with the detailed
description of the invention, serve to explain the principles of the
present invention.

[0011] FIG. 1 illustrates a first implementation of an integrated
conductive and inductive charging solution;

[0012]FIG. 2 illustrates a second implementation of an integrated
conductive and inductive charging solution; and

[0014] Embodiments of the present invention provide an apparatus and
method for efficiently integrating inductive and conductive charging
systems. The following description is presented to enable one of ordinary
skill in the art to make and use the invention and is provided in the
context of a patent application and its requirements.

[0015] Various modifications to the preferred embodiment and the generic
principles and features described herein will be readily apparent to
those skilled in the art. Thus, the present invention is not intended to
be limited to the embodiment shown but is to be accorded the widest scope
consistent with the principles and features described herein.

[0016] FIG. 1 illustrates a first implementation of an integrated
conductive and inductive charging solution 100. Charging solution 100
includes both a conductive rectifier stage and an inductive rectifier
stage that have been integrated together to provide charging energy to an
energy storage system (ESS, e.g., a battery, a battery module, a battery
pack, and the like). Different embodiments and implementations offer
differing levels of integration appropriate for the intended application,
some of which are described herein. The conductive rectifier stage
includes an inverter switching circuit 105 that operates in conjunction
with an output smoothing circuit 110 to produce a steady DC voltage from
a first AC line voltage 115. Many implementations include an optional
isolation transformer 120 to isolate the DC load of the energy storage
system from first AC line voltage 115, particularly those implementations
for electric vehicle charging and telecommunications. When employed, a
primary winding of isolation transformer 120 is coupled to an output of
inverter switching circuit 105 and a secondary winding of isolation
transformer 120 is coupled to an input of output smoothing circuit 110.

[0017] In addition, many charging solutions include a preconditioner 125
that provides any necessary/desirable switching, electromagnetic
interference (EMI) filtering, and other conditioning of first AC line
voltage 115 before energizing inverter switching circuit 105. Similarly
many charging solutions include a postconditioner 130 that provides any
necessary/desirable switching, EMI filtering, and other conditioning of
smoothed DC voltage from output smoothing circuit 110 before application
to the ESS.

[0018] Charging solution 100 further includes a controller 135 that
generates appropriate control signals to operate inverter switching
circuit 105. There are many different types of inverter switching
circuits which will have variations regarding the details of the control
signals (e.g., pulse width modulation or other modulation schemes and the
like) necessary for their operation, all within the scope of the present
invention. Controller 135 employs a set of charging parameters gathered
from a sensing system distributed throughout charging solution 100. The
set of charging parameters includes VAC for first AC line voltage
115 measured by a voltage sensor 140 and an IAC for current provided
by first AC line voltage 115 to inverter switching circuit 105 measured
by a current sensor 145. The set of charging parameters further includes
VBAT for the ESS measured by a voltage sensor 150 and IBAT for
the ESS measured by a current sensor 155.

[0019] Output smoothing circuit 110 includes a number of components, and
like inverter switching circuit 105, there are many types and topologies
of output smoothing circuit 110 which will have variations on the details
necessary for their operation, all within the scope of the present
invention. In the preferred embodiment, the preferred level of
integration and component reuse is in the output smoothing circuits of
the rectifier stages as further described herein. Thus a representative
output smoothing circuit is described in more detail, with the
understanding that other output smoothing circuits may vary slightly or
dramatically, and all within the scope of the present invention.

[0020] Output smoothing circuit 110 includes a diode bridge 160 having a
pair of inputs coupled to the secondary winding and a pair of outputs
coupled to opposing terminals of a capacitor 165. A first output of diode
bridge 160 is coupled to a first terminal of capacitor 165 through an
inductor 170, and a second output of diode bridge 160 is coupled to a
second terminal of capacitor 165 through current sensor 155. An optional
snubber circuit 172 is coupled between outputs of diode bridge 160 and
capacitor 165. There are many different implementations and possible uses
of snubber circuit 172, such as providing protection, improving
performance, and the like. In charging solution 100, a representative
snubber circuit 172 includes a snubber resistor 175 and series-coupled
snubber diode 180 (cathode of snubber diode 180 is coupled to snubber
resistor 175) is in turn coupled in parallel with inductor 170 to the
first output terminal of diode bridge 160 and first terminal of capacitor
165. A snubber capacitor 182 is coupled from the cathode of snubber diode
180 to the second output terminal of diode bridge 160. In some
embodiments, diode bridge 160 may be replaced with an active rectifier
component or circuit.

[0021] The inductive rectifier stage includes an off-board electronics
assembly 184 that is energized by a second AC line voltage 186 and is
electromagnetically coupled, using an inductive transformer 188, to the
ESS. The nature and type of coupling and level of integration varies
based upon implementation and application details. Charging solution 100
provides a second inverter switching circuit as part of off-board
electronics assembly 184, with the second inverter switching circuit
responsive to control signals from controller 135. Charging solution 100
preferably includes at least some minimal secondary/slave controller
functions within off-board electronics assembly 184 that is responsive to
primary/master controller functions within controller 135. In such a
configuration, the controller function is distributed on-board and
off-board with primary/master control functions disposed on-board. In
some implementations, the on-board and off-board controller functions may
be more equivalent or have other cooperative modes, including the
off-board controller functions in some situations predominate.

[0022] Charging solution 100 is implemented using a second output
smoothing circuit 190 coupled to both a secondary winding of induction
transformer 188 and to capacitor 165. Output smoothing circuit 190
includes a diode bridge 192 having a pair of inputs coupled to the
secondary winding of induction transformer 188 and a pair of outputs
coupled to the opposing terminals of capacitor 165. A first output of
diode bridge 192 is coupled to the first terminal of capacitor 165
through an inductor 194, and a second output of diode bridge 192 is
coupled to the second terminal of capacitor 165 through current sensor
155.

[0023] It is a feature of charging solution 100 that the conductive
rectifier stage is wholly disposed on the apparatus with the ESS (e.g.,
an electric vehicle) while a portion of the inductive rectifier stage is
disposed on the apparatus and a portion disposed off the apparatus. Each
rectifier stage is shown with its own energizing AC line voltage, but in
some cases it may be that these AC line voltages are shared. The AC line
voltages may be single-phase or multiphase, and may be the same voltage
level (e.g., 110 VAC, 220 VAC, or the like) or provide different
energization voltages (e.g., 220 VAC for first AC line voltage 115 and
110 VAC for second AC line voltage 186) and currents (e.g., 16 A and 40 A
respectively). It is a feature of charging solution 100 that controller
135 provides operational control over both inverter switching circuits.
Controller 135 is disposed on the apparatus, and in the preferred
embodiments wholly disposed on the apparatus. In some implementations,
some controller functions specifically required for the inductive
rectifier stage or other feature may be incorporated into off-board
electronics assembly 184. Controller 135 and off-board electronics
assembly 184 preferably include wireless communication modules enabling
bidirectional data flow through a wireless link 196. The data flow
includes instructions for the inverter switching circuit and a set of
sensor parameters for second AC line voltage 186, including VAC and
IAC. In some implementations, controller 135 may provide battery
sensor data and other operational information and off-load some tasks to
off-board electronics assembly 184. Off-board electronics assembly 184
may, in some configurations, provide higher level data, such as power
available, time to complete charge, and the like, or provide information
that controller 135 establishes this information.

[0024] Operation of charging solution 100 will be described in a specific
narrow context as an aid to understanding the present invention. The
present invention includes this context, as well as other contexts.
charging solution 100 is included as part of an EV and uses the
conductive rectifier stage as a primary charging modality. As well-known,
a user mates a physical power connector coupled to an energy source,
utility grid power or the like to a complementary physical power
connector on the apparatus to enable charging. Controller 135 operates
inverter switching circuit 105 to produce an appropriate AC voltage level
and output smoothing circuit 110 rectifies and smooths this voltage to
the desired DC voltage which is applied to the ESS for charging.

[0025] This is often sufficient for many applications, but it does require
some work on the part of the user to engage the physical power connector
and to actuate the charging process. As charging stations continue to
proliferate, some will be installed with inductive charging capacity.
This will be true for both private and public charging stations. In
either case, when the EV is enabled for inductive charging in addition to
the conductive charging capability, this provides more options to the
user. It is often true that inductive charging systems are less
efficient, though they can be more convenient for the user. Less
efficiency typically means that, holding other variables and conditions
constant, it will take longer to charge the ESS to a desired level using
inductive charging than would be the case using conductive charging. In
some cases this may not be inconvenient to the user, such as when a
standard overnight charge at inductive charging efficiency sufficiently
charges the ESS. The user is able to install off-board electronics
assembly 184 in the floor of a garage, for example, drive over the
off-board electronics, and initiate (automatically or manually) a
charging process that will be complete the next time the EV is to be
driven.

[0026] In a public charging station scenario, it can be the case that the
charging station includes both a conductive charging bay as well as an
inductive charging bay. The user is able to select either bay in the
event one or both are open, or select a queue that represents the
shortest-time-to-charge based upon efficiency and number of preceding
vehicles in each queue.

[0027] Even when the user chooses conveniences associated with inductive
charging, charging solution 100 enables the user in any of the scenarios
to choose conductive charging as appropriate. This could be the case when
the user, after initiating inductive charging, realizes that an
unexpected use is required of the EV, and the inductive charging solution
will not sufficiently charge the ESS before the EV is needed. The user is
able to engage the conductive charging capacity and have the EV ready
when needed.

[0028] In these scenarios, independent, non-concurrent operation of the
rectifiers stages is described. In some embodiments, it is possible for
the user to energize both rectifier stages concurrently and achieve even
greater charging speed. These various scenarios are preferably tuned and
optimized by adjusting components of the output smoothing circuits.

[0029] A critical component of the output smoothing circuits for
concurrent operation are the inductors (i.e., inductor 170 and inductor
194). In FIG. 1, each smoothing circuit has its own inductor (i.e.,
inductor 170 and inductor 194) that is sized to store and discharge
energy responsive to a maximum instantaneous power provided by each
output smoothing circuit, without concurrent operation of the rectifier
stages. By doing this, each rectifier stage is able to operate
concurrently and independently, each inductor sized properly. As noted
herein, typically inductive rectification is less efficient than
conductive rectification. In such cases, when each rectifier stage is
energized by similar AC line voltages, inductor 194 may be sized smaller
(and thus be less costly) than inductor 170. It should be noted that in
some implementations, charging solution 100 dispenses with inductor 170
and inductor 194.

[0030] In some implementations it is necessary or desirable to use a
single inductor yet enable the possibility of concurrent operation. In
such cases it is possible to eliminate inductor 194 by increasing the
size of inductor 170 to store/discharge a maximum instantaneous power
provided by both output smoothing circuits. It may be less costly, or
otherwise advantageous, to use a single larger inductor than two smaller
inductors. Of course, elimination of inductor 194 may require rerouting
of the connections shown to properly use inductor 170 with output
smoothing circuit 190.

[0031] In other implementations it is necessary or preferable to prevent
both rectifier stages from operating concurrently. In such cases it is
also possible to use a single shared inductor, but it need be sized based
upon the maximum instantaneous power of the output smoothing circuit
discharging the greatest instantaneous power. Typically this will be the
output smoothing circuit associated with the conductive rectifier stage.

[0032]FIG. 2 illustrates a second implementation of an integrated
conductive and inductive charging solution 200. Charging solution 200
substitutes a modified output circuit 205 of the inductive rectifier
stage for output smoothing circuit 190 shown in FIG. 1. Output circuit
205 is coupled directly to the secondary winding of isolation transformer
120 at the inputs of diode bridge 160. Output circuit 205 of the
preferred embodiment includes a power connector and relays/contactors
that selectively couple the secondary winding of inductive transformer
188 to diode bridge 160. In some cases, it may be necessary or desirable
to provide an additional set of relays coupled to the secondary winding
of isolation transformer 120 to not short inductive transformer 188
during inductive charging. This configuration uses output smoothing
circuit 110 for both rectifier stages. Note that in this configuration
implementation there is no concurrent operation of the rectifier stages.
In some instances it may be possible to enable concurrent operation by
adjustment to one or both of the output circuits. Other arrangements and
intercoupling of components in the stages are also possible in other
embodiments to share differing numbers of components, based upon needs,
performance, and resource costs.

[0034] There are many different topologies and configurations for
rectifier stages in general and the inverter switching circuits and
output smoothing circuits specifically. The present invention is
adaptable to many, if not all of these, and offers conveniences and
flexibility to users. The present invention is not limited to mobile
apparatus having rechargeable energy storage systems. There are mobile
inductive charging stations that employ paddles, for example, that could
be used in cooperation with a non-mobile apparatus having a primary
conductive rectifier stage.

[0035] An aspect of the present invention addresses efficiently coupling
the off-board electronics assembly to the apparatus and improve inductive
charging efficiency. The off-board electronics assembly may be integrated
into a floor of charging station, or may be disposed on the floor and a
ramp provided to aid in alignment. In some implementations, particularly
for public charging stations, robotic systems may move and reposition the
off-board electronics assembly to optimize electromagnetic coupling.
Those robotic systems may be disposed in the charging station, the
vehicle, or both.

[0036] The systems and methods are preferably implemented using a
microprocessor executing program instructions from a memory, the
instructions causing the apparatus to perform as described herein. The
system and methods above has been described in general terms as an aid to
understanding details of preferred embodiments of the present invention.
In the description herein, numerous specific details are provided, such
as examples of components and/or methods, to provide a thorough
understanding of embodiments of the present invention. One skilled in the
relevant art will recognize, however, that an embodiment of the invention
can be practiced without one or more of the specific details, or with
other apparatus, systems, assemblies, methods, components, materials,
parts, and/or the like. In other instances, well-known structures,
materials, or operations are not specifically shown or described in
detail to avoid obscuring aspects of embodiments of the present
invention.

[0037] Reference throughout this specification to "one embodiment", "an
embodiment", or "a specific embodiment" means that a particular feature,
structure, or characteristic described in connection with the embodiment
is included in at least one embodiment of the present invention and not
necessarily in all embodiments. Thus, respective appearances of the
phrases "in one embodiment", "in an embodiment", or "in a specific
embodiment" in various places throughout this specification are not
necessarily referring to the same embodiment. Furthermore, the particular
features, structures, or characteristics of any specific embodiment of
the present invention may be combined in any suitable manner with one or
more other embodiments. It is to be understood that other variations and
modifications of the embodiments of the present invention described and
illustrated herein are possible in light of the teachings herein and are
to be considered as part of the spirit and scope of the present
invention.

[0038] It will also be appreciated that one or more of the elements
depicted in the drawings/figures can also be implemented in a more
separated or integrated manner, or even removed or rendered as inoperable
in certain cases, as is useful in accordance with a particular
application.

[0039] Additionally, any signal arrows in the drawings/Figures should be
considered only as exemplary, and not limiting, unless otherwise
specifically noted. Furthermore, the term "or" as used herein is
generally intended to mean "and/or" unless otherwise indicated.
Combinations of components or steps will also be considered as being
noted, where terminology is foreseen as rendering the ability to separate
or combine is unclear.

[0040] As used in the description herein and throughout the claims that
follow, "a", "an", and "the" includes plural references unless the
context clearly dictates otherwise. Also, as used in the description
herein and throughout the claims that follow, the meaning of "in"
includes "in" and "on" unless the context clearly dictates otherwise.

[0041] The foregoing description of illustrated embodiments of the present
invention, including what is described in the Abstract, is not intended
to be exhaustive or to limit the invention to the precise forms disclosed
herein. While specific embodiments of, and examples for, the invention
are described herein for illustrative purposes only, various equivalent
modifications are possible within the spirit and scope of the present
invention, as those skilled in the relevant art will recognize and
appreciate. As indicated, these modifications may be made to the present
invention in light of the foregoing description of illustrated
embodiments of the present invention and are to be included within the
spirit and scope of the present invention.

[0042] Thus, while the present invention has been described herein with
reference to particular embodiments thereof, a latitude of modification,
various changes and substitutions are intended in the foregoing
disclosures, and it will be appreciated that in some instances some
features of embodiments of the invention will be employed without a
corresponding use of other features without departing from the scope and
spirit of the invention as set forth. Therefore, many modifications may
be made to adapt a particular situation or material to the essential
scope and spirit of the present invention. It is intended that the
invention not be limited to the particular terms used in following claims
and/or to the particular embodiment disclosed as the best mode
contemplated for carrying out this invention, but that the invention will
include any and all embodiments and equivalents falling within the scope
of the appended claims. Thus, the scope of the invention is to be
determined solely by the appended claims.